Bug 1729

Summary:	use an implicit return value - AE_AML_NO_RETURN_VALUE
Product:	ACPI	Reporter:	Luming Yu (luming.yu)
Component:	ACPICA-Core	Assignee:	Robert Moore (Robert.Moore)
Status:	CLOSED CODE_FIX
Severity:	high	CC:	acpi-bugzilla
Priority:	P2
Hardware:	i386
OS:	Linux
Kernel Version:	2.4, 2.6	Subsystem:
Regression:	---	Bisected commit-id:
Attachments:	a patch for fixing this issue implicit return patch -- against 2.6

Description Luming Yu 2003-12-22 19:23:32 UTC

FreeBSD does have a workaround for this.  We use an implicit return value:
http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/contrib/dev/acpica/psparse.c.diff?r1=1.20&r2=1.21&f=h

-Nate

On Fri, 19 Dec 2003, Brown, Len wrote:
> AML is like C -- if there is no return statement from a routine (method)
> then nothing gets returned.
>
> Unfortunately the microsoft implementation of the AML interpreter
> behaves as if there is a return statement, and so bugs in AML get
> through windows validation.
>
> For this to work on the ACPICA AML interpreter, you need to insert the
> missing return statements in the AML -- we don't have a workaround for
> this type of BIOS bug.
>
> -Len
~

Comment 1 Luming Yu 2003-12-22 19:25:33 UTC

Created attachment 1713 [details]
a patch for fixing this issue

Just port Free BSD's workaround to linux

Comment 2 Len Brown 2004-03-24 18:16:14 UTC

Seen on Tecra 8000:
http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=107458
ACPI-0109: *** Error: No object was returned from [\_SB_.LNKA._STA] (Node 
c118688c), AE_NOT_EXIST 

Seen on Compaq Evo N620c in bug 2083
    ACPI-1120: *** Error: Method execution failed [\_TZ_.C202] (Node cff7ed20),
AE_AML_NO_RETURN_VALUE

\

Comment 3 Luming Yu 2004-04-01 00:52:36 UTC

*** Bug 2083 has been marked as a duplicate of this bug. ***

Comment 4 Luming Yu 2004-06-03 23:55:36 UTC

Created attachment 3065 [details]
implicit return patch -- against 2.6

There are two different way for returning value.
1. through pointer: call_return_desck (for interface : acpi_evaluate_object)
2. push the result object onto result_stack.

My patch fixes the second scenario.

Notice: This patch merge the previous patch (Iwasaki San iwasaki@freebsd.org)

Comment 5 Len Brown 2004-11-03 15:32:27 UTC

A different patch for this shipped in ACPICA 20040816
which is included in Linux-2.6.9 -- closing